Soluble transferrin receptor and mutations in hemochromatosis and transferrin genes in a general Catalan population.

BACKGROUND: The measurement of soluble transferrin receptor (sTfR) has been proposed as a valuable marker of erythropoietic activity and iron status. However, the possibility that mutations in HFE and/or transferrin genes have a direct effect on this parameter has not been sufficiently investigated. The present report addresses this point in the general population. METHODS: Serum sTfR, ferritin, iron and transferrin, as well as the H63D and the C282Y polymorphisms of the HFE gene and the TF C1/C2 polymorphism of the transferrin gene, were analysed in 348 subjects. RESULTS: We observed significant and independent associations of serum sTfR with sex (2.68+/-1.27 mg/L in men vs. 2.25+/-1.33 in women; P=0.002), H63D polymorphism (2.61+/-1.34 in wild type homozygotes vs. 2.28+/-1.25 in carriers of one or two mutated alleles; P=0.009), and serum iron concentration (r=-0.17; P=0.002). CONCLUSION: The H63D mutation of the HFE gene has a moderate but significant influence on sTfR concentration in the general population, the presence of one or two mutated alleles being associated with an average of 0.27 mg/L less sTfR than nonmutated homozygotes.

Early onset hereditary papillary renal carcinoma: germline missense mutations in the tyrosine kinase domain of the met proto-oncogene.

PURPOSE: Hereditary papillary renal carcinoma (HPRC) is characterized by a predisposition to multiple, bilateral papillary type 1 renal tumors caused by inherited activating missense mutations in the tyrosine kinase domain of the MET proto-oncogene. In the current study we evaluated the clinical phenotype and germline MET mutation of 3 new HPRC families. We describe the early onset clinical features of HPRC. MATERIALS AND METHODS: We identified new HPRC families of Italian (family 177), Spanish (family 223) and Cuban (family 268) descent. We evaluated their clinical features, performed MET mutation analysis by denaturing high performance liquid chromatography and DNA sequencing, and estimated age dependent penetrance and survival using Kaplan-Meier analysis. We characterized renal tumors by histology and fluorescence in situ hybridization. RESULTS: Identical germline MET c.3522G --> A mutations (V1110I) were identified in families 177 and 268 but no evidence of a founder effect was found. Affected members of family 223 carried a germline c.3906G --> C.3522G --> A MET mutation (V1238I). Age dependent penetrance but not survival was significantly earlier for the c.3522G -->A mutation than for the c.3906G --> A mutation in these HPRC families. Trisomy of chromosome 7 and papillary renal carcinoma type 1 histology were detected in papillary renal tumors. CONCLUSIONS: HPRC can occur in an early onset form. The median age for renal tumor development in these 3 HPRC families was 46 to 63 years. HPRC associated papillary renal tumors may be aggressive and metastasize, leading to mortality. Median survival age was 60 to 70 years. Families with identical germline mutations in MET do not always share a common ancestor. HPRC is characterized by germline mutations in MET and papillary type 1 renal tumor histology.

Prevalence of BRCA1 and BRCA2 germline mutations in young breast cancer patients: a population-based study.

Our aim was to estimate the prevalence of mutations in the BRCA1 and BRCA2 genes among unselected incident cases of breast cancer in young women. We identified 158 incident breast cancer cases diagnosed before age 46 years in predefined geographic areas in Girona and Tarragona, Spain, during 1995-1997. Of these, 136 (86%) provided information on family history of cancer and were screened for BRCA1 and BRCA2 mutations. Nine of the 136 (6.6%) were found to carry BRCA deleterious mutations (MUT) (1 BRCA1 and 8 BRCA2), and 20 were detected with rare BRCA variants of unknown significance (UV). Both MUT and US BRCA alterations were more frequent in younger patients: 7 (11.6%) MUT and 12 (19.3%) UV carriers were found in the group of 62 patients younger than 40 years, whereas 2 (2.7%) MUT and 9 (12%) US carriers were identified in the group of 74 patients aged 40-45. Family history of breast and ovarian cancers suggestive of hereditary condition (at least 2 first- or second-degree relatives affected with breast cancer or at least 1 relative affected with ovarian cancer or early-onset breast cancer) was absent for 5 of 9 MUT carriers. This suggests that BRCA screening policies based on family history of cancer would miss a considerable proportion of BRCA mutations. Mutations in the BRCA1 and BRCA2 genes explain at least 10% of breast cancer cases diagnosed before age 40 years. The contribution of these genes to early-onset breast cancer is likely to be even higher given that certain UV cases might be disease-associated.